BMW N55 BM3 F-Chassis Tuning Guide

Pro Tuning Freaks (PTF) bootmod3 flash tunes are a popular option for the newer F and G chassis BMW's. Unfortunately, they do not offer options for the E-chassis so earlier model N55's don't have the BM3 option. PTF BM3 offers an excellent web interface and mobile app for easy N55 tuning. Bootmod3 also comes with a few off-the-shelf map options with great features. F-chassis N55 owners in the market for a tune should definitely consider bm3. In this guide, we discuss N55 bootmod3 tunes, stages, supporting mods, and hp gains.

Bootmod3Pin

About BM3 N55 Flash Tunes

Bm3 offers off-the-shelf (OTS) flash tunes for the N55, along with custom tuning capability. OTS tunes from bootmod3 are highly tested and proven. Additionally, they're easy to install and well priced for the performance gains. The costs of bm3 tunes are as follows:

  • $595 software license
  • $50 map pack

The software license is essential to use the bm3 tuning software. Purchase of the license includes one OTS map of your choice. You then have the option to buy the map pack bundle for an additional $50. This unlocks all of the off-the-shelf maps for the N55 F-chassis. It's not necessary if you plan to simply flash a tune and never look back. However, the map pack bundle is a good option if you're planning on adding more mods in the future or want the flexibility of switching tunes.

Bootmod3 N55 Maps:

  • Stage 0+ (M2 factory tune)
  • Stage 1. (ACN 91, 91 octane, 93 octane)
  • Stage 2. (ACN 91, 91 octane, 93 octane, E30, race gas)
  • Stage 2+ (E30, race gas)

Above are the stages available for the N55, and the octane ratings are individual maps within each stage. It's a good time to note - your BMW N55 may be PWG or EWG depending on the specific model and year. The N55 bm3 stage 2+ tunes are only for the later EWG models. We're also skipping over the bm3 stage 2h tunes, which are for an upgraded hybrid turbo.

In the rest of this article we discuss the above N55 bm3 stages and recommended supporting mods for each. We'll also provide rough horsepower estimates for each stage and fuel. Actual power may vary on many factors such as PWG or EWG, difference in dynos, additional supporting mods like meth injection, etc. That said, many F chassis N55 engines are EWG. We'll base the power off EWG N55's running the recommended supporting mods on a dynojet.

*Final note - we recommend replacing your N55 spark plugs prior to running bm3 flash tunes, especially if your spark plugs are old.

N55 OEM Spark Plugs

N55 1-Step Colder Spark Plugs

OEM N55 Ignition Coils

N55 BM3 Stage 1 HP Gains & Mods

Supporting Mods: Intake

Stage 1 bm3 tunes may be a bit too soft for some. These tunes are pretty basic, entry level tunes that don't offer E30 or race gas options. This is especially true on BMW's like the M2, M135i, M235i, etc that have a higher starting point for horsepower. They're great tunes for those that want just a little more. Though peak gains may not be massive there are plentiful power and torque gains on the lower-end and mid-range.

Bootmod3 stage 1 tunes are also a great starting point since no supporting mods are required. Simply flash the tune and go. However, we do recommend an intake. If not for the minor intake horsepower gains the sounds are worth it.

Bm3 Stage 1 Horsepower

ACN 91 octane: 315-325whp / 345-355wtq

91 octane: 320-330whp / 350-360wtq

93 octane: 330-340whp / 355-365wtq

Expect N55 bm3 stage 1 horsepower in the ballpark of 310whp to 335whp. Again, the peak power gains may not sound overly impressive but there are bigger gains to be had in the mid-range. It's also not too bad for a conservative tune. ACN (AZ, CA, NV) 91 octane is poor fueling and results in the worst power. Standard 91 octane also isn't excellent fueling. You may consider octane booster or an alternative method of running 93 octane for the best N55 stage 1 results.

N55 Bootmod3 Stage 2 HP Gains & Mods

Supporting Mods: Intake + FMIC

Stage 2 BM3 tunes begin rolling in enough boost that heat soak becomes a concern. An intercooler upgrade is an excellent mod for any stage, but highly recommended for these stage 2 tunes. Without an intercooler the charge air will quickly become too hot resulting in performance loss. A downpipe is also a great mod that you may consider for the stage 2 tunes. However, we're saving that mod to discuss for stage 2+.

BM3 Stage 2 Horsepower

ACN 91 octane: 335-345whp / 370-385wtq

91 octane: 340-350whp / 375-390wtq

93 octane: 350-360whp / 380-400wtq

Race gas: 370-390whp / 410-430wtq

E30 blend: 370-390whp / 410-430wtq

N55 bootmod3 stage 2 horsepower comes in around 335-390whp. As boost increases fuel and supporting mods become more and more important. It's part of the reason the power range is so wide for stage 2 tunes. Race gas and E30 blends will offer the biggest N55 horsepower gains by a pretty solid margin. If you opt for stage 2 bm3 tunes without an intercooler upgrade you may see these numbers on glory runs. However, after a few back-to-back pulls the N55 will quickly start dropping power.

BMW N55 Stage 2+ BM3 Tunes

Supporting mods: Intake + FMIC + DP

Finally, we're including the upgraded downpipe for N55 bm3 stage 2+ tunes. Again, these tunes are only available for the EWG models. If you're PWG and want bigger gains then stage 2 with a downpipe is a great option. Anyways, these stage 2+ tunes are the most aggressive OTS offering from BM3. We highly recommend running full bolt-ons (the mods above) for these tunes. A downpipe will add nice power gains and makes the turbos job a bit easier thanks to less back-pressure. You'll also notice slightly quicker turbo spool with a downpipe.

Lastly, these tunes are only available for E30 and race gas. If running FBO with E30 fuel you may consider fueling mods or methanol injection. Otherwise, keep an eye on AFR's to ensure you're not leaning out.

BM3 Stage 2+ Horsepower

Race gas: 400-420whp / 420-450wtq

E30 blend: 400-425whp / 420-460wtq

These power estimates for N55 bm3 stage 2+ tunes may be a bit on the aggressive side. They're pretty optimistic, but possible with the proper supporting mods and fueling. For more power you'll want to consider custom tuning options and/or methanol injection. If you're still not satisfied then an upgraded turbo will likely come into play. A few N55 EWG models have come in around 450whp on the stock turbo. However, most should expect the stock turbo to reach its limit in the 420-430whp range.

N55 Bootmod3 Flash Tunes Summary

The N55 is a fairly capable engine straight from the factory. However, a tune and basic bolt-ons can push the N55 to the next level. Bootmod3 offers excellent OTS tuning options for the N55 with plenty of stages and maps for fueling. It's also loaded with some great features like data-logging, speed limiter removal, exhaust burbles, and plenty more. Bm3 tunes offer a little something for almost every N55 owner.

Stage 1 tunes are a great option for those just wanting a little more power, however some see them as too conservative. If you're running E30 or race gas then stage 2 tunes are an excellent option. Power comes in around 335-390whp with N55 bm3 stage 2 tunes. Finally, those wanting the most out of their N55 should consider stage 2+ tunes available for the EWG models. The only maps available on stage 2+ are E30 and race gas, but will result in peak power around or north of 400whp. Pretty solid results for the stock turbo.

What's your experience with bm3? Or are you considering tuning with bm3?

Leave a comment and let us know!

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6 thoughts shared

  1. Nice article.

    I’m planning to go Stage 1 with BootMod3 OTS. Do you know how much they increase the PSI boost when going stage 1?

    Also thinking about installing new coils and possibly upgrading to colder spark plugs.

    Your thoughts?

    1. Comment author image

      Tyson Crosby

      says:

      I know this is WAY past when you asked this, however. I just installed BM3 on my ’14 535i. Other mods consists of aluminum charge pipe and Burger Motorsports intake. According to the BM3 live dashboard my maximum PSI is 21.3 and WOT.

    1. Hi Martin,

      That can be a bit of a toss up. It’s generally recommended to move to 1-step colder plugs for each 75-100 horsepower added. Many add even more power than that without moving to colder spark plugs.

      That said, the NGK 97506 1-step colder plugs are an excellent choice. With a modest stage 1 tune there likely is not any real reason or need to move to a 1-step colder plug, but it also isn’t a bad idea.

      Best Regards,
      Zach

  2. Hpfp stage2 is a must for stage2+ “e30 plus” maps. Its is 1700$ part+ labor cost adds to you your FBO to run this map….but well worth it because weak point in n55 is fuiling first and than turbo.